Heat the vegetable broth in a medium saucepan and keep it warm over low heat throughout the cooking process.

In a large, heavy-bottomed pan, heat olive oil over medium heat. Add the diced onion and cook for 4-5 minutes until softened and translucent, stirring occasionally.

Add the arborio rice to the pan and stir constantly for 2-3 minutes until the grains are lightly toasted and coated with oil. Pour in the white wine and stir until completely absorbed.

Add one ladle of warm broth to the rice and stir frequently until absorbed. Continue adding broth one ladle at a time, stirring frequently and allowing each addition to be absorbed before adding more. This process should take about 20-25 minutes.

When the rice is almost tender but still has a slight bite, stir in the peas and cook for 3-4 minutes until they are tender and bright green.

Remove from heat and stir in the butter, parmesan cheese, lemon zest, lemon juice, and half of the chopped mint. Season with salt and pepper to taste. The risotto should be creamy and flow slightly when plated.

Divide the risotto among serving bowls and garnish with the remaining fresh mint and additional parmesan cheese if desired. Serve immediately while hot and creamy.